YjbH regulates virulence genes expression and oxidative stress resistance in .

We previously reported that disruption of the gene reduced virulence of . In this study, we found virulence in both silkworms and mice was restored by introducing the gene but not the gene to both and genes-disrupted mutants, suggesting that , the gene downstream to the gene in a two-gene operon-, is responsible for this phenomenon. We further observed a decrease in various surface-associated proteins and changes in cell envelope glycostructures in the mutants. RNA-seq analysis revealed that disruption of the and the genes resulted in differential expression of a broad range of genes, notably, significant downregulation of genes involved in virulence and oxidative stress. Administration of N-acetyl-L-cysteine, a free-radical scavenger, restored the virulence in both the mutants. Our findings suggested that YjbH plays a role in staphylococcal pathogenicity by regulating virulence gene expression, affecting the bacterial surface structure, and conferring resistance to oxidative stress in a host.